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Biomedical subjects

W M Guterbock

Publications and source records attributed to W M Guterbock.

12 recordsLinked to original sources

Financial analysis of alternative treatments for clinical mastitis associated with environmental pathogens.

For two large California dairy herds with twice daily milking, 171 infected quarters of lactating cows with mild clinical mastitis were randomly assigned to one of three treatment groups. Group A (50 cows) was treated with 62.5 mg of intramammary amoxicillin every 12 h for three milkings. Group C (50 cows) was treated with 200 mg of intramammary cephapirin every 12 h for two milkings. Group O (71 cows) was treated with 100 U of intramuscular oxytocin every 12 h for three milkings. Clinical cure rates did not differ among treatment groups. The cost per episode of clinical mastitis was higher ($54.47) for group C than for groups A ($38.53) or O ($34.88). Group O had a higher incidence of relapse (41%), and a greater percentage of group O cows (65%) experienced an additional mastitic event in the enrolled lactation than did cows in groups A and C. Treatment had no effect on the mean number of nonsalable milkings (24.7) associated with mastitis in the lactation interval subsequent to enrollment on the trial. Twenty-two percent of the cows accrued more than 30 nonsalable milkings and produced 55% of the total nonsalable milkings associated with mastitis. There was no treatment effect on total milk production, fat production, or time to removal of the enrolled cows from the herd.

Amoxicillin↗

Efficacy of a dried colostrum powder in the prevention of disease in neonatal Holstein calves.

The efficacy of a dried colostrum powder, DCW Concentrate, as a colostrum supplement or substitute was tested using four groups of 15 calves. Physical condition and IgG status were examined during the first 30 d of life. Calves were fed the dried colostrum powder (group A), pooled colostrum (group C), or both (groups B and D) 2 h after birth. Calves fed 85 g of the dried colostrum powder dissolved in 3 kg of whole milk (group A) had significantly lower IgG concentrations 24 h after birth than calves of the other groups. Administration of 85 g of the dried colostrum powder plus 3 kg of colostrum (group C) did not lead to significantly higher IgG concentrations 24 h after birth than did administration of 3 kg of colostrum alone (group B). Calves fed 85 g of the dried colostrum powder plus 1.5 kg of colostrum (group D) had an IgG concentration at 24 h of age that was not significantly different from that of calves given 3 kg of colostrum (group B). Morbidity and mortality rates were not significantly different among groups. One calf died in each of groups A and B; no losses occurred in groups C and D. Body weight increase was not significantly different among groups.

Animals↗

Evaluation of milk antibiotic residue screening tests in cattle with naturally occurring clinical mastitis.

Milk from 172 commercial cows with mild to moderate clinical mastitis was tested with five antibiotic residue detection assay systems. One hundred cows were treated with one of two intramammary beta-lactam antibiotics, and the remaining 72 cows were treated with intramuscular oxytocin. Milk samples were collected pretreatment, twice after therapy, and again 21 d following the initiation of treatment. Presumptive false-positive assay results were tabulated from all pretreatment and 21-d milk samples and from samples collected following oxytocin therapy. The percentage of false-positive results was 43.6, 37.7, 81.7, 2.6, and 18.8% for the CITE probe (beta-lactam), Delvotest-P, Charm Farm, LacTek (beta-lactam), and Bacillus stearothermophilus var. calidolactis disk assay, respectively. In four of the assay systems, average SCC were significantly higher in samples yielding false-positive results than in those with negative results. Specificity and sensitivity were estimated for each assay system, and, based on these estimates, positive and negative predictive value curves were graphed as the prevalence of milk samples containing detectable concentrations of exogenous antibiotic residues in the sample population was varied from 0 to 100%.

Animals↗

Efficacy of intramammary antibiotic therapy for treatment of clinical mastitis caused by environmental pathogens.

For three California dairy herds with bulk tank SCC < 200,000/ml, twice daily milking, and no mastitis vaccine, 254 quarters with mild clinical mastitis were randomly assigned to three groups. Group A (n = 74) was treated with 62.5 mg of intramammary amoxicillin every 12 h for three milkings. Group C (n = 75) was treated with 200 mg of intramammary cephapirin every 12 h for two milkings. Group O (n = 105) was treated with 100 units of intramuscular oxytocin every 12 h for two or three milkings. Aseptic pretreatment quarter samples revealed 94 (37%) coliforms, 65 (26%) environmental streptococci, 34 (13%) other bacteria, and 61 (24%) with no isolate on bovine blood agar plates. Contagious pathogens were not isolated. Clinical cure (return of quarter and milk to normal) and bacterial cure (absence of primary pathogen isolated pretreatment) were assessed at milking 8 and d 20 after initial treatment. No difference existed in clinical (67.6, 67.7, or 66.7%) or bacterial (43.9, 55.0 or 49.1%) cure rate among groups. Clinical cure rates did not differ when quarters were grouped by etiology, but clinical cure rates for quarters with pathogens other than streptococci or coliforms were lower in group O.

Amoxicillin↗

Microbiologic investigation of an epizootic of mastitis caused by Serratia marcescens in a dairy herd.

An epizootic of subclinical and clinical mastitis caused by Serratia marcescens was investigated in a 1,000-cow dairy farm in California. Serratia marcescens was isolated from 13 to 18% of composite milk samples obtained from lactating dairy cows. During monthly milk sampling performed during a 4-month period, S marcescens was isolated from 38.8 to 62.3% of composite milk samples obtained from cows from which S marcescens was previously isolated. Few cows infected with S marcescens had evidence of clinical mastitis. Somatic cell count value was associated with isolation of S marcescens. Cows with somatic cell counts greater than 500,000 were 5.48 times as likely to have intramammary infections with S marcescens, compared with cows with somatic cell count less than or equal to 500,000. Lactation number also was associated with S marcescens intramammary infection. After adjusting for the effect of lactation number, cows with high somatic cell count values were 2.98 times as likely to have intramammary infection with S marcescens, compared with cows with low somatic cell counts. Infection with S marcescens was independent of days in lactation, production string, and daily milk production. Eleven months after the beginning of the epizootic, S marcescens was isolated from organic bedding samples obtained from the dairy. Despite numerous attempts, other sources of S marcescens could not be identified on this dairy.

Animals↗

Pathological and toxicological studies of calves fed a high concentration cotton seed meal diet.

Feeding a high concentration of cotton seed meal to young calves resulted in death with lesions compatible with gossypol toxicity. Calves were fed two different commercially prepared rations. Free gossypol concentrations in different lots of the 17% protein ration varied from 250 to 380 ppm, and the 13% protein ration varied from 40 to 240 ppm. Serum sorbitol dehydrogenase elevation was the most consistent clinical pathological finding. The mean serum sorbitol dehydrogenase concentrations for moribund, hospitalized, and clinically healthy calves were 277, 34, and 45 units/liter. The mean for sorbitol dehydrogenase concentration for healthy calves not fed cotton seed meal was 18 units/liter. Gross lesions included severe effusion of a high protein content fluid into the body cavities of most calves, edema of the mesentery, and hepatomegaly. The most consistent histological lesion was severe centrilobular hepatic necrosis. Elevated levels of liver gossypol were demonstrated. The mean liver gossypol concentration for three calves was 41.7 micrograms/g on a wet weight basis.

Animal Feed↗

Coccidia and intestinal nematodes of East Central Illinois cats.

In a fecal examination survey (1975-1976) of 217 cats from laboratory colonies, a humane society shelter, and homes in east central Illinois, Toxocara mystax eggs were found in 32%, Toxascaris leonina eggs in 6%, Ancylostoma eggs in 9%, Capillaria eggs in 4%, Isospora felis oocysts in 23%, Isospora rivolta oocysts in 24%, and Toxoplasma or Besnoitia oocysts in 1%. The laboratory and humane shelter cats were the most heavily infected. Isospora felis and I rivolta could not be transmitted to 2 pups by feeding oocysts from the cat or to 2 other pups by feeding the organs of mice that had been fed the oocysts.

Ancylostomiasis↗

Performance of various tests used to screen antibiotic residues in milk samples from individual animals.

The 10-point Milk and Dairy Beef Quality Assurance Program was developed collaboratively by the National Milk Producers Federation and the American Veterinary Medical Association and is designed to promote and document the responsible use of antibiotics in the dairy industry. One area of emphasis in this program is testing of individual animals for antibiotic residues after a specified post-treatment withdrawal time. We examined the performance of various assay systems on milk samples from individual cows. These assays are used at present on bulk tank milk samples by regulatory agencies, processing plants, producers, and veterinarians to detect the presence of beta-lactam antibiotics. A high proportion of false-positive results was obtained for both the pretreatment milk samples from cows with clinical mastitis and the milk samples obtained 21 days after initial therapy (nonantibiotic and antibiotic) for the treatment of mastitis. A high proportion of false-positive outcomes was obtained from the milk of clinically normal cows that had not received any medication for at least 30 days prior to evaluation. The results indicate a serious problem in the use of some assays that were designed to evaluate residues bulk tank milk samples to analyze samples from individual cows. This error in assay specificity results in the unjustifiable discarding of milk that meets regulatory standards and may be misused to accuse the producer or veterinarian of not adhering to regulatory guidelines. Maintaining a safe, high-quality milk supply is a constant goal of the dairy industry, which must be provided the appropriate tools and techniques to meet this challenge.

Animals↗